Validation Of Numerical Procedure For Assessment Of Centrifugal Pump Cavitation Erosion

Validation Of Numerical Procedure For Assessment Of Centrifugal Pump Cavitation Erosion

 

این مقاله روش ارزیابی اعتبار سنجی جدیدی را برای خوردگی ناشی از کاویتاسیون در پمپ های سانتریفوژ ارایه می دهد. این بررسی برای دو ساختار پمپ ها انجام می شود:

-         پروانه  های  Between-bearings

-         پروانه های Overhung

این روش ترکیبی از دینامیک محاسباتی جریان ناپایدار سه بعدی و آنالیز عددی رفتار حباب های کاویتاسیون می باشد. در این روش شکل گیری تا از بین رفتن حباب ها در جریان سه بعدی غیر یکنواخت در نظر گرفته می شود.

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Validation Of Numerical Procedure For Assessment Of Centrifugal Pump Cavitation Erosion
حجم: 427 کیلوبایت

CFD Analysis of Off-design Centrifugal Compressor Operation and Performance

CFD Analysis of Off-design Centrifugal Compressor

Operation and Performance

 

 

Abstract

Mathematical modelling

This paper presents some of the results from a Master’s thesis research into the performance and operation of a centrifugal compressor at off-design operating conditions using advanced computational fluid dynamics (CFD) techniques. ANSYS CFX is the CFD solver used in this blind study to evaluate the ability of modern CFD software to predict the performance of centrifugal compressors operating at highly complex flows regimes.

The off-design cases considered included compressor operations at 60%, 70%, 80%, 90%, 100% and 105% of the on-design rotational speed. Speed lines were generated for each case and compared to experimental measurements. The predicted results were found to match very closely with the experimental measurements.

The flow within the centrifugal compressor stage was also examined by considering various performance parameters and making use of three-dimensional flow visualizations. This allowed for a better understanding of the fluid behavior within the centrifugal compressor.

Lastly, the benefits of unsteady (time accurate) simulation on centrifugal compressor performance predictions were investigated. The results obtained showed that unsteady simulations noticeably improve the accuracy of the compressor performance predictions.

 

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CFD Analysis of Off-design Centrifugal Compressor Operation and Performance
حجم: 1.32 مگابایت

 

Assessment Of A Mixing Plane Method For CFD Analysis

Multistage Centrifugal-Pumps: Assessment Of A Mixing Plane 

Method For CFD Analysis

Abstract

An accurate CFD investigation allows a thorough knowledge of the fluid dynamic field inside a multistage centrifugal pump but only a correct interpretation of its results grants a well-founded prediction of the machine performance curves. The paper introduces the assessment of an improved methodology to predict head-flow and efficiency characteristics of industrial pumps in real operating conditions. The described approach is based on standard CFD analysis and experimental tests.

 

The numerical procedure is built-up of three different steps:

· CFD investigation of the single impeller and diffuser domains;

· impeller-diffuser interaction analysis;

· evaluation of the whole multistage pump performance curves by pressure field

 

interpretation and taking into account real machine secondary phenomena. The stage computational model is made up of two 3D fluid domains with overlapping: one of them is aimed to simulate the diffuser and is related to a stationary reference frame while the other one models the impeller and is referred to a rotating system.

Moreover the impeller–diffuser interaction is studied by the employment of a mixing plane technique. Numerical results are then compared to the real pump performance test at the actual working conditions in order to validate the proposed methodology.

The paper will discuss all approach details and the main CFD features involved.

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Multistage Centrifugal-Pumps: Assessment Of A Mixing Plane Method For CFD Analysis
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